Sanitizing device and method for sanitizing articles

ABSTRACT

The invention provides an apparatus for sanitizing a plurality of articles, which comprises a housing enclosing a sanitizing zone, the housing having a seal for preventing leakage of gas or fluid from the sanitizing zone; a pump for introducing an antimicrobial fluid into the sanitizing zone; and a pump for withdrawing the fluid from the sanitizing zone. The device also includes at least one high power microwave source and at least one ultraviolet irradiating source, or a microwave source that also generates ultraviolet radiation. Preferably, the gas is a halogen, such as chlorine, bromine, or iodine, or a gas or fluid containing chlorine or bromine ions, but it can be ozone or another gas which kills bacteria, microbes, viruses, and other pathogens. The fluid can also be sprayed droplets or vaporized sodium hypochlorite, or similar antiseptic agent.

This application claim the benefit of Provisional application Ser. No.60/337,654, filed Nov. 7, 2001.

FIELD OF THE INVENTION

This invention relates to an apparatus for sanitizing articles such asenvelopes, parcels, or packages sent by mail or courier, and moreparticularly to an apparatus which uses high energy microwave andultraviolet radiation, along with a gas to kill contaminants such asbacteria and viruses on the surface or inside of the envelope orpackage.

BACKGROUND OF THE INVENTION

Machines resembling assembly lines through which food articles and thelike pass use several different energy or radiation sources to sanitizethe foodstuff, for example, to kill E. coli and botulism bacteria in theproduction plant. Cobalt 60, a radioactive material which emits gammaradiation, kills such bacteria, but the radioactive radiation it emitsmay expose plant workers to a hazard. Similarly, x-rays and electronbeams can effectively kill undesirable organisms without rendering thefoodstuff inedible, but they too present environmental hazards, andtheir cost of installation and power consumption may make themundesirable or impractical for either small scale or mass treatment ofmail, packages, and the like.

It is therefore an object of the invention to provide a sanitizingapparatus which will effectively kill pathogens, such as bacteria,viruses, spores, mold, and the like on the surface and the interior ofpackages and envelopes.

SUMMARY OF THE INVENTION

The foregoing disadvantages of prior devices can be overcome by thepresent invention by providing an apparatus for sanitizing a pluralityof articles, which comprises a housing enclosing a sanitizing zone, thehousing having a seal for preventing leakage of gas or fluid from thesanitizing zone; a pump for introducing an antimicrobial fluid into thesanitizing zone; and a pump for withdrawing the fluid from thesanitizing zone. The device also includes at least one high powermicrowave source and at least one ultraviolet irradiating source, or amicrowave source that also generates ultraviolet radiation. Preferably,the gas is a halogen, such as chlorine, bromine, or iodine, or a gas orfluid containing chlorine or bromine ions, but it can be ozone oranother gas which kills bacteria, microbes, viruses, and otherpathogens. The fluid can also be sprayed droplets or vaporized sodiumhypochlorite, or similar antiseptic agent.

The invention also provides a method for killing microbes and pathogenson a plurality of articles, the method comprising: moving articles intoa sanitizing zone; introducing an antimicrobial fluid in the presence ofultraviolet and microwave energy; and retaining the articles in thesanitizing zone for a period of time sufficient to kill microbial matteron the articles.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention may beunderstood by reviewing the following detailed description of thepreferred embodiments in conjunction with the attached drawings inwhich:

FIG. 1 is a schematic drawing of a first embodiment the sanitizingapparatus of the present invention;

FIG. 2 is a block diagram of circuitry for controlling a sanitizingapparatus according to an embodiment of the present invention;

FIG. 3 is a schematic drawing of a second embodiment of the presentinvention; and

FIG. 4 is a schematic drawing of a third embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, a first embodiment of the presentinvention is shown in FIG. 1. The sanitizing device 10 includes conveyorbelt 12 including a continuous belt 14 driven by rollers 16. Some of therollers 16 are rotated by gears 18 driven by an electric motor 20. As ina conventional conveyor belt, the belt 14 carries along a plurality ofarticles 22 such as envelopes, packages, containers and the like. Thesanitizing apparatus 10 of the present invention can therefore be usedin a post office or other government facility, or in the mailroom of anoffice, bank, hotel, hospital, factory, or other business institution.Since it includes a conveyor 14, it can be installed as a module in amail sorting or handling line.

The sanitizing assembly 10 of the present invention uses a plurality ofultraviolet and microwave radiation sources 24 to irradiate thesanitizing zone 19 through which packages or envelopes 22 pass throughon the conveyor belt 14. Optionally, an x-ray detection system (notshown) can be used. The optional x-ray system can visualize the contentsof the package or envelope to determine whether it contains anyexplosive or other hazardous device or substance. A metal sensing device17 at the front of the conveyor such as a magnetometer or capacitancesensor recognizes packages with metallic packaging material, and an arm(not shown) shunts them aside to avoid exposure of metal to microwaveradiation.

Additionally, the apparatus 10 includes a series of spigots 26 whichintroduce a fluid, such as a halogen gas (e.g., chlorine, iodine orbromine), ozone, a peroxide containing gas, chlorine dioxide gas, or achlorine or chlorine and oxygen containing compound, such as calcium orsodium chloride or calcium or sodium hypochlorite. Other sources ofchlorine ions or chlorine and oxygen containing ions may also be used,as may a carbohydrate containing substrance or fluid, such as soy beanderivative. Fluid containing chlorine atoms, such as aqueous sodiumhypochlorite (common household bleach) can be vaporized or sprayed intothe chamber 19 as a mist of droplets. In such a case, the fluid willinclude chlorine and oxygen containing atoms, molecules or ions whichwill kill bacteria, viruses, or other microbial contaminants on thesurface of the package 12.

Ultraviolet and microwave radiation would ionize or energize the gas orfluid so that it can react with and destroy biological material. Themicrowave and ultraviolet radiation by itself would not necessarily heator irradiate the package sufficiently to kill bacteria or othercontaminants, but would help the chlorine, ozone, peroxide or other gasto work more effectively.

Provision can be made to treat both sides of an envelope simultaneously,for example, by providing a mesh conveyor belt or a mechanism (notshown) to flip the envelopes over to complete treatment of a secondside. In either case, the article 22 is held for a time sufficient toallow the energized ions, atoms, or molecules to kill the microbes onthe surface of the article. U.S. Pat. Nos. 3,817,703 and 5,364,645 bothaddress using various forms of electromagnetic radiation to killpathogens and microorganisms, and set forth suggested time and energylevels which may be effective in the present apparatus and method. Thecontents of those patents are incorporated by reference herein.

In a second embodiment, shown schematically in FIG. 3, the articlesanitizer 10 can be in the form of a module 11 to add to an existingconveyor belt C used in a postal or sorting facility. Like the previousembodiment, module 11 could include one or more means for introducing anantimicrobial fluid into a sanitizing zone 19 defined by the housing H.The module 11 also includes one or more ultraviolet and microwaveradiation sources which may be separate or included in a single unit, asshown in FIG. 3. The second embodiment, like the first, includes a pump21 for removing antimicrobial fluid from the sanitizing zone or chamber19. The chamber 19, in any embodiment, should preferably include aseries of baffles and gaskets to prevent the antimicrobial gas or otherfluid, as well as the radiation, from escaping from the chamber 19.

In yet another embodiment, illustrated in FIG. 4, the sanitizingapparatus 10 of the present invention may be a module 11 which, in lieuof a conveyor 19, a housing 19 which rests on a table or similar support(not shown). The housing 19 contains the articles 22 which undergosanitation in an enclosed space S. The space S has walls which allow anoperator to insert articles 22, and then close the housing 19 to preventleakage of antimicrobial fluid and radiation from the housing 19. Theapparatus 10 also includes a pump 26 for introducing the fluid into thechamber or space and a pump 21 for removing the fluid and filteringsolid matter there from.

The present invention can also advantageously employ a perforatingmechanism 28 to make tiny holes in the envelope or other package toallow the gas to penetrate the interior of the parcel 22, killing anypathogens contained therein. In the embodiment shown in FIG. 1, themicroperforating apparatus 28 is a series of pins mounted on an armwhich raises and lowers through a reciprocal motion driven by amotor-cam combination 25. The arm raises and lowers as directed by anelectric eye or other detector, which would lift the arm sufficiently toallow a package to pass underneath. It can be lowered so that the tineson the arm perforate the package wrapper slightly without harming thecontents. The pinpricks in the package would allow the chlorine or otherfluid to enter the interior of the package in order to destroy anthraxor other biohazard, for example, or to allow the spores or microbes toexit the package where they will be destroyed by the antimicrobialfluid. Alternatively, a series of rollers studded with pins or teeth canbe used to provide the perforations (not shown). The rollers should moveup and down to adjust for different package sizes, but should have aspring or other opposing force mechanism pressing them downward towardthe package 22 so that they lightly perforate the cover layers of thepackage.

A laser 54, such as an excimer laser (see FIG. 2) can provide also lightenergy to kill microbes and other pathogens. Examples of methods usinglaser and ultraviolet radiation to disinfect foods may be found in U.S.Pat. No. 5,364,645 (Lagunas-Solar), and U.S. Pat. No. 3,817,703(Atwood), referenced above. Optionally, an x-ray or other radioactivesource can be added, to be used in combination with the high powermicrowave and UV energy sources incorporated into the present invention.

The apparatus 10 also includes a feedback control system 56, whoseoperation may be understood with reference to FIG. 2. The 56 systemincludes a controller 40 to control the amount of energy and gassesreleased during the operation of the system. Controller 40 includespreprogrammed ROM to control the motor 20 which drives the conveyor belt14, either incrementally, or linearly.

Controller 40 also controls one or more solenoid or similar type gas orfluid valves 42 through a feedback loop so that the proper disinfectingconcentration of gas (for example, ozone, peroxide, chloride, orchlorine) is fed from the gas source 44 into the treatment chamber 19(FIG. 1) of the apparatus 10. The system 10 is activated by an on/offswitch 46 which activates the motor 48 driving the conveyor 14. Thecontroller 40 also switches and controls the microwave radiation source50, the ultraviolet light source 52, and the optional laser light source54. The controller 40 either includes, or works in tandem with afeedback control system 56 to regulate the flow of gas, and theintensity of light or energy in the treatment chamber 19. The system 10preferably includes a gas evacuation and recirculation system 58including a filter for particulate matter, so that gas used in thetreatment apparatus 10 can be reclaimed and recycled or reused.

Controller 40 can also be any suitable type of controller circuit and,for example, can consist of a microprocessor controller. Various typesof controllers suitable for use in a device such as the presentinvention are known in the art. Accordingly, controller 40 will not bedescribed in detail. Briefly, however, controller 40 includes ROM forstoring one or more operating programs. Controller 40 can also includeRAM that can be programmed by the user through use of an alphanumericcontrol pad (not shown). Of course, controller 40 can also includevarious other types of memories and/or peripherals or peripheralinterfaces as desired. Controller 40 can also be preprogrammed or can beprogrammed by the user to automatically run in cycles.

The UV light source may be a monochromatic beam of pulsed ultraviolet orultraviolet laser radiation having a wavelength of about 240–280 nm. Anytype of ultraviolet source producing enough energy to kill pathogens,including Hg lamps emitting 20 nm UV radiation, or low intensity(0.10–10 W/m²) continuous wave polychromatic (broad band) UV radiationcan be used. Also desirable would be low intensity (0.10 to 10 W/m²)continuous wave polychromatic (broad band) UV radiation (4.88 eV).Pulsed (20 nsec) ultraviolet laser radiation of 193 nm (6.42 eV) mayalso be used under certain conditions.

In operation, with reference to FIGS. 1 and 2, the conveyor belt 14moves when the on/off switch 46 is turned “on”. The high intensity UVlight source 52 and microwave radiation source 50 irradiate the parcels,packages or envelopes 22 on the conveyor belt 14. The controller 40opens the solenoid or other control on the gas or fluid control valve42, allowing gas or fluid to enter from its source or container, such asa gas tank 44, to enter the chamber 19. The high intensity UV andmicrowave radiation ionizes the gas inside the chamber 19, which in turnkills microbes, such as anthrax or other harmful bacteria or viruses.The contaminated gas is removed by the pump 21, which connects to afilter 23 to remove harmful bacteria and other particulate matter. Itmay also cleanse the gas so that some or all may be reused.

Various modifications in the construction of the present apparatus 10may be made to adapt to a particular type of package, or to use it, forexample, to decontaminate food. While several embodiments have beenshown and described, it will be apparent that other adaptations andmodifications can be made without departing from the spirit and scope ofthe invention.

I claim:
 1. An apparatus for sanitizing a plurality of envelopes,parcels, or packages sent by mail or courier, comprising: a housingenclosing a sanitizing zone, the housing having a seal for preventingleakage of gas from the sanitizing zone; a source of antimicrobialfluid: a pump for introducing an antimicrobial fluid into the sanitizingzone; means for making a plurality of holes in an envelope, parcel orpackage to allow the antimicrobial fluid to penetrate the interior ofthe envelope, parcel or package; a pump for withdrawing theantimicrobial fluid from the sanitizing zone; and at least one microwavesource and at least one ultraviolet irradiating source.
 2. An apparatusin accordance with claim 1, wherein the pump for withdrawing theantimicrobial fluid includes a filter for removing particulate matterfrom the fluid.
 3. An apparatus in accordance with claim 1, wherein theantimicrobial fluid is ozone, a peroxide, a halogen gas, or chlorinedioxide.
 4. An apparatus in accordance with claim 1, wherein themicrowave and ultraviolet sources emit microwave and ultraviolet energyto ionize the antimicrobial fluid in the sanitizing zone.
 5. Anapparatus in accordance with claim 4, wherein the housing mountsadjacent a conveyor apparatus such that the conveyor carries thearticles through the sanitizing zone.
 6. An apparatus in accordance withclaim 4, wherein the housing additionally comprises a conveyor formoving envelopes, parcels, and packages through the sanitizing zone. 7.A method for destroying microbes on a plurality of envelopes, parcels,or packages sent by mail or courier, the method comprising: moving theplurality of envelopes, parcels or packages into a sanitizing zone;making a plurality of holes in the envelopes, parcels or packages toallow antimicrobial fluid to penetrate the interior thereof; introducingthe antimicrobial fluid in the presence of ultraviolet and microwaveenergy; and retaining the envelopes, parcels or packages in thesanitizing zone for a period of time sufficient to kill microbial matteron and in the interior of the envelopes, parcels or packages.
 8. Amethod according to claim 7, wherein the holes are pinpricks.
 9. Amethod according to claim 7, wherein the ultraviolet and microwaveenergy ionize the antimicrobial fluid when the envelopes, parcels, andpackages are in the sanitizing zone.